From 7ca73020a5b26599d539083e413784e79891107e Mon Sep 17 00:00:00 2001 From: Jacopo Mondi Date: Fri, 26 Jan 2024 15:04:59 +0100 Subject: [PATCH 1150/1215] media: uapi: Document meta pixel format for PiSP BE config Add format description for the PiSP Back End configuration parameter buffer. Signed-off-by: Jacopo Mondi Reviewed-by: Naushir Patuck --- .../userspace-api/media/v4l/meta-formats.rst | 1 + .../media/v4l/metafmt-pisp-be.rst | 56 +++++++++++++++++++ 2 files changed, 57 insertions(+) create mode 100644 Documentation/userspace-api/media/v4l/metafmt-pisp-be.rst --- a/Documentation/userspace-api/media/v4l/meta-formats.rst +++ b/Documentation/userspace-api/media/v4l/meta-formats.rst @@ -15,6 +15,7 @@ These formats are used for the :ref:`met metafmt-bcm2835-isp-stats metafmt-d4xx metafmt-intel-ipu3 + metafmt-pisp-be metafmt-rkisp1 metafmt-sensor-data metafmt-uvc --- /dev/null +++ b/Documentation/userspace-api/media/v4l/metafmt-pisp-be.rst @@ -0,0 +1,56 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. _v4l2-meta-fmt-rpi-be-cfg: + +************************ +V4L2_META_FMT_RPI_BE_CFG +************************ + +Raspberry Pi PiSP Back End configuration format +=============================================== + +The Raspberry Pi PiSP Back End memory-to-memory image signal processor is +configured by userspace by providing a buffer of configuration parameters +to the `pispbe-config` output video device node using the +:c:type:`v4l2_meta_format` interface. + +The PiSP Back End processes images in tiles, and its configuration requires +specifying two different sets of parameters by populating the members of +:c:type:`pisp_be_tiles_config` defined in the ``pisp_be_config.h`` header file. + +The `Raspberry Pi PiSP technical specification +`_ +provide detailed description of the ISP back end configuration and programming +model. + +Global configuration data +------------------------- + +The global configuration data describe how the pixels in a particular image are +to be processed and is therefore shared across all the tiles of the image. So +for example, LSC (Lens Shading Correction) or Denoise parameters would be common +across all tiles from the same frame. + +Global configuration data are passed to the ISP by populating the member of +:c:type:`pisp_be_config`. + +Tile parameters +--------------- + +As the ISP processes images in tiles, each set of tiles parameters describe how +a single tile in an image is going to be processed. A single set of tile +parameters consist of 160 bytes of data and to process a batch of tiles several +sets of tiles parameters are required. + +Tiles parameters are passed to the ISP by populating the member of +``pisp_tile`` and the ``num_tiles`` fields of :c:type:`pisp_be_tiles_config`. + +Raspberry Pi PiSP Back End uAPI data types +========================================== + +This section describes the data types exposed to userspace by the Raspberry Pi +PiSP Back End. The section is informative only, for a detailed description of +each field refer to the `Raspberry Pi PiSP technical specification +`_. + +.. kernel-doc:: include/uapi/linux/media/raspberrypi/pisp_be_config.h